Self Aligning Automated Material Handling System

Abstract

A semiconductor workpiece processing system comprises at least one processing tool; a transport section configured to transport carriers to and from the processing tool; and a transport vehicle movably mounted on the transport section; wherein the transport vehicle is configured to: sense a location of a transport carrier alignment feature; adjust a location of a transport vehicle gripper based on the location of the transport carrier alignment feature; sense an attitude of the gripper at a point of engagement with the transport carrier; and adjust the location of the gripper based on the attitude of the gripper.

1 . A method of performing alignment in a material handling system, the method comprising:
 moving a gripper of a transport vehicle towards to a transport carrier;   sensing a location of an alignment feature on the transport carrier;   adjusting a location of the gripper based on the location of the alignment feature; and   storing the location of the gripper in a memory of the automated material handling system.   
     
     
         2 . The method of  claim 1 , further comprising:
 sensing an attitude of the gripper at a point of engagement between the gripper and the transport carrier; and   adjusting the location of the gripper based on the attitude.   
     
     
         3 . The method of  claim 1 , further comprising comparing a signal strength of a pod alignment sensor in the material handling system with a predetermined signal strength. 
     
     
         4 . The method of  claim 1 , further comprising presenting an alert when the gripper is outside an alignment tolerance zone. 
     
     
         5 . The method of  claim 1 , wherein sensing a location of an alignment feature on the transport carrier comprises linearly moving a sensor on the gripper over the alignment feature. 
     
     
         6 . The method of  claim 1 , wherein sensing a location of an alignment feature on the transport carrier comprises tracing a circumference of the alignment feature with a sensor on the gripper. 
     
     
         7 . The method of  claim 1 , wherein sensing a location of an alignment feature on the transport carrier comprises moving a sensor on the gripper over the alignment feature in an arcurate pattern. 
     
     
         8 . The method of  claim 1 , further comprising sensing an edge of a flange of the gripper on the transport carrier. 
     
     
         9 . The method of  claim 8 , further comprising rotationally aligning the gripper with the gripper flange such that the gripper is juxtaposed to the edge of the gripper. 
     
     
         10 . The method of  claim 2 , wherein adjusting the location of the gripper comprises calculating a distance to move the gripper based on the attitude of the gripper. 
     
     
         11 . The method of  claim 2 , further comprising storing the attitude of the gripper in a memory of the automated material handling system. 
     
     
         12 . A semiconductor processing system comprising:
 at least one processing tool;   a transport section configured to transport carriers to and from the processing tool; and   a transport vehicle movably mounted on the transport section;   wherein the transport vehicle is configured to:   sense a location of a transport carrier alignment feature;   adjust a location of a transport vehicle gripper based on the location of the transport carrier alignment feature;   sense an attitude of the gripper at a point of engagement with the transport carrier; and   adjust the location of the gripper based on the attitude of the gripper.   
     
     
         13 . The semiconductor processing system of  claim 12 , wherein the transport vehicle comprises a pod alignment feature having a pod alignment sensor. 
     
     
         14 . The semiconductor processing system of  claim 13 , wherein the pod alignment sensor comprises a capacitive sensor. 
     
     
         15 . The semiconductor processing system of  claim 12 , wherein the transport vehicle comprises:
 a gripper member having a lower portion pivotally mounted to an upper portion of the gripper member; and   at least one attitude sensor mounted between the upper portion and the lower portion, the attitude sensor configured to sense a displacement of the lower portion relative to the upper portion.   
     
     
         16 . A carrier transport system comprising:
 at least one carrier; and   a transport vehicle configured to grip and to transport the at least one carrier;   wherein a gripper of the transport vehicle is configured to sense a location of a carrier alignment feature and is further configured to adjust a location of the gripper based on the location of the carrier alignment feature.   
     
     
         17 . The carrier transport system of  claim 16 , wherein the gripper comprises a pod alignment feature having a pod alignment sensor. 
     
     
         18 . The carrier transport system of  claim 17 , wherein the pod alignment sensor comprises a capacitive sensor. 
     
     
         19 . A carrier transport system comprising:
 at least one carrier; and   a transport vehicle configured to grip and to transport the at least one carrier;   wherein the transport vehicle is configured to sense an attitude of a transport vehicle gripper at a point of engagement with the carrier and is further configured to adjust a location of the transport vehicle gripper based on the attitude of the transport vehicle gripper.   
     
     
         20 . The carrier transport system of  claim 19 , wherein the transport vehicle comprises:
 a gripper module having a lower portion pivotally mounted to an upper portion; and   at least one attitude sensor mounted between the upper portion and the lower portion, the attitude sensor configured to sense a displacement of the lower portion relative to the upper portion.